This application is related to U.S. Pat. Nos. 5,380,037; 6,092,832; 6,196,573; and 6,237,944, the contents of which are also incorporated herein by reference thereto.
Vehicles are supplied with driver's side airbag modules; generally the driver's side airbag module is located in the center of the steering wheel. This is also the same location where a horn-activating switch has traditionally been mounted.
Various mounting mechanisms have been used for securing the inflatable restraint module to a support structure in a vehicle, such as a steering wheel or dashboard. In one known mounting mechanism, mounting bolts are provided passing from a rear of the support structure and threadably engaging nuts mounted on the inflatable restraint module. In another known mounting mechanism for a vehicle steering wheel, sleeve members mounted to the inflatable restraint module and surrounding the mounting bolts may be forced into contact with a plate forming the supporting structure on a hub portion of the steering wheel to complete a circuit for actuating a horn.
Eventually, the horn-activating switch was adapted for mounting on the underside of the airbag module wherein the module was mounted in a “free floating” arrangement to allow the user to activate the horn by applying an activation pressure to the module and move the driver's side airbag module into a horn activation position. Such horn-activating switches react to a user-applied force to the cover in an effort to sound the horn. For example, and in such a system the entire airbag module moves as force is applied to actuate the horn.
Most original equipment manufacturers (OEMs) style their driver's side airbag modules and steering wheels by using a contoured gap between the two parts. This gap primarily allows the driver's side airbag module to move freely relative to the Class A surfaces of the wheel (free movement is required for a floating horn system). However, the OEMs also contour these gaps so that they contribute to the overall style and appearance of the driver's side airbag module and steering wheel assembly.
Once attached the module is capable of movement through the application of a user-applied force wherein a horn circuit is completed in accordance with known technologies. The module is biased in a non-contact or open circuit position by a biasing spring. A current apparatus for a snap-in floating horn system uses the combination of three components at each point of attachment. The three components are a locking pin extending from the driver's side airbag module, a locking spring attached to the wheel, and a plastic insulator also attached to the wheel. These three components work in conjunction and can be arranged to create a two, three, or four-point driver's side airbag module attachment to the wheel. During module attachment, the locking pin goes through a slot in the insulator, displaces a locking spring attached to the insulator or the steering wheel, and locks into the wheel after the locking spring moves back to its original position thereby engaging a groove in the locking pin.
The slot size within the insulator determines the free movement or amount of play the pin will have. If the slot is too small, the locking pin will be restricted, and the floating horn will bind. Therefore, the slot has to be sufficiently larger than the size of the locking pin to allow for free movement of the driver's side airbag module. However, the large slot size also allows the pin and the driver's side airbag module attached thereto to move from side-to-side (x-direction or cross car direction) and up-down (y-direction or orthogonal with respect to axis of steering column or orthogonal with respect to the horn activation direction). This movement may create non-uniform gaps between the driver's side airbag module and steering wheel and/or spokes.